Is the 'Isha Prayer the last act of the day? And is it permissible to do things after it, such as watching television and talking with the family?

The 'Isha' prayer does not necessarily have to be the last act of the day. It is permissible to work and converse after it if the activity is beneficial, such as discussing knowledge, matters concerning Muslims, speaking with a guest, or anything else necessitated by need. This is supported by the Ahadith of Ibn 'Umar and 'Umar. The disapproval of conversing after it stems from the possibility that it might lead to staying up late and missing the Fajr prayer, engaging in idle talk, missing the night vigil (Qiyam al-Layl), or to ensure that the day concludes with prayer. However, this disapproval is lifted if there is a need or if the conversation is for good, such as reading Hadith, studying Fiqh, or speaking with a guest.